The subject matter of the present invention relates generally to athletic shoes having cleated soles and in particular to such shoes in which the cleats are molded integral with the outer sole of the shoe of resilient material for superior traction and cushioning when used on artificial turf and other hard surfaces such as rubberized asphault tracks, streets, basketball floors, tennis courts, etc. The cleated sole of the present invention is provided with large area wear cleats at the opposite sides of the heel for longer wear and to provide greater lateral stability to prevent injury due to twisted ankles and the like. In addition, another pair of large area wear cleats may be provided on the opposite sides of the toe portion of the sole.
The shoe sole of the present invention is useful on many types of athletic shoes worn for sports such as track or jogging, requiring straight ahead running, and for sports also involving lateral movement such as football, soccer, baseball, basketball, tennis and golf. The sole is suitable for use on hard surfaces such as artificial turf as well as on natural grass or dirt since the cleats are designed to be self-cleaning.
It has previously been proposed in U.S. Pat. No. 3,793,750 of W. J. Bowerman, granted Feb. 26, 1974, to provide an athletic shoe suitable for use on artificial turf and other hard surfaces with an improved sole of studs or cleats of resilient material molded integral with the outer sole of the shoe of a polygon shape. While this shoe provides superior traction and cushioning when running on hard surfaces, its useful lifetime is somewhat limited because of undue wear of the sole, especially by some types of runners who drag their heels. In addition, such previous shoe has some lateral instability due to a shoe upper of synthetic fabric and a thick multi-layered sole, including a cushion midsole layer. This lateral instability was reduced by outwardly flaring the sides of the heel portion of the sole as shown in pending U.S. patent application Ser. No. 688,843 by G. L. Hollister et al, filed May 21, 1976, now U.S. Pat. No. 4,043,058, granted Aug. 23, 1977.
Both of the above problems have been solved by the sole of the present invention including a pair of heel cleats of larger area provided on the opposite sides of the heel portion of the sole and in some cases, a pair of toe cleats of large area on the opposite sides of the toe portion of such sole. Thus the large cleats provided on the outside edge of the sole prevent undue wear while the large cleats provided adjacent the inside edge of the sole function primarily to provide greater lateral stability. This has been accomplished while maintaining the superior cushioning and traction characteristics of the cleated sole of U.S. Pat. No. 3,793,750 and without adding any appreciable weight.
There have been other attempts to provide shoe soles for use on artificial turf including those employing cleats of cylindrical or conical shape molded integral with the outer sole, as shown in U.S. Pat. No. 3,932,950 of G. J. Taber, granted Jan. 20, 1976. However, such shoe also suffers from problems of undue wear and lateral instability. In addition, in order to provide adequate traction using round cleats, this shoe employs an extremely large number of small cleats closely spaced to one another which has the added disadvantage that such a sole becomes quickly clogged with dirt and grass when used on natural turf because such sole is not self-cleaning. Self-cleaning cleated soles for football shoes used on natural turf are old, as shown in U.S. Pat. No. 2,888,756 of N. B. Parsons, granted June 2, 1959. However, these soles are not suitable for artificial turf and other hard surfaces because they are molded of a rigid synthetic plastic material called "Neolite", and are provided with pointed edges as the ground engaging surfaces of such cleats, so they do not provide sufficient traction or cushioning.